Geothermal heat exchange using coil assemblies

ABSTRACT

A heat-exchange system includes a casing and a coil assembly disposed within the casing. The coil assembly may include a supply inlet configured to receive heat-exchange fluid and a first manifold disposed downstream of the supply inlet. The first manifold may include a supply conduit and a number of manifold outlets. The coil assembly may include a number of exchange conduits coupled, at a first end, to one of the plurality of manifold outlets. A second manifold may be disposed downstream of the first manifold, and may include a return conduit and a number of manifold inlets, where each exchange conduit is coupled, at a second end, to one of the manifold inlets. A return outlet may be configured to return the heat-exchange fluid.

TECHNICAL FIELD

Embodiments of the present disclosure relate to geothermal systems configured to facilitate heat exchange. More specifically, embodiments of the disclosure relate to heat-exchange assemblies that utilize coil assemblies to facilitate heat exchange within a heat-exchange cavity.

BACKGROUND

Conventional closed-loop geothermal heat-exchange systems include a heat pump coupled to a single heat-exchange conduit, or multiple heat-exchange conduits, that extends into the ground, makes a 180 degree turn at a U-bend, and returns to the heat pump. These conventional systems typically require the heat-exchange conduit to extend approximately 200 feet deep for every ton of heating or cooling energy. Thus, for example, a two-ton system may require drilling a borehole approximately 400 feet deep. Other conventional closed-loop geothermal systems may include a large pond-loop structure disposed within a pond or other surface body of water. Accordingly, it would be desirable to be able to perform geothermal heat exchange without needing to drill as deeply as in conventional geothermal systems, and in locations where a surface body of water may not be available.

SUMMARY

Embodiments of the disclosure include a geothermal system for facilitating heat exchange. The geothermal system includes a heat-exchange assembly having a coil assembly disposed within a casing.

In an Example 1, a heat-exchange system includes a casing; and a coil assembly disposed within the casing, the coil assembly comprising: a supply inlet configured to receive heat-exchange fluid; a first manifold disposed downstream of the supply inlet, the first manifold comprising a supply conduit and a plurality of manifold outlets; a plurality of exchange conduits, wherein each exchange conduit is coupled, at a first end, to one of the plurality of manifold outlets; a second manifold disposed downstream of the first manifold, the second manifold comprising a return conduit and a plurality of manifold inlets, wherein each exchange conduit is coupled, at a second end, to one of the plurality of manifold inlets; and a return outlet configured to return the heat-exchange fluid.

In an Example 2, the system of Example 1, the casing comprising a perforated polyvinyl chloride (PVC) pipe.

In an Example 3, the system of either of Examples 1 or 2, the casing comprising an annular wall.

In an Example 4, the system of Example 3, the casing further comprising a lower wall at least partially closing a first end of the annular wall.

In an Example 5, the system of either of Examples 3 or 4, the casing further comprising an upper wall at least partially closing a second end of the annular wall.

In an Example 6, the system of any of Examples 3-5, the casing further comprising at least one aperture defined in the annular wall, the at least one aperture being configured to allow water to pass therethrough.

In an Example 7, the system of any of Examples 1-6, further comprising at least one additional coil assembly disposed within the casing.

In an Example 8, the system of Example 7, wherein the at least one additional coil assembly is operatively coupled to the coil assembly.

In an Example 9, the system of Example 8, wherein the coil assembly and the at least one additional coil assembly are operatively coupled in series and/or in parallel.

In an Example 10, the system of any of Examples 1-9, wherein at least one of the first manifold and the second manifold has a length of at least approximately three feet.

In an Example 11, the system of any of Examples 1-10, the plurality of exchange conduits comprising between 75 and 125 exchange conduits.

In an Example 12, the system of Example 11, the plurality of exchange conduits comprising 117 exchange conduits.

In an Example 13, the system of any of Examples 1-12, each of the plurality of exchange conduits having a length of between at least approximately 15 feet and 25 feet.

In an Example 14, the system of Example 13, each of the plurality of exchange conduits having a length of at least approximately 19.5 feet.

In an Example 15, the system of any of Examples 1-14, wherein the plurality of exchange conduits are arranged in a parallel orientation with respect to each other.

In an Example 16, the system of any of Examples 1-15, wherein at least one of the plurality of exchange conduits is coiled with respect to a central axis.

In an Example 17, the system of Example 16, further comprising at least one spacer disposed between adjacent loops of the at least one of the plurality of exchange conduits.

In an Example 18, the system of Example 17, the at least one spacer comprising a plurality of spacers positioned to maintain an at least approximately constant gap between each pair of adjacent loops.

In an Example 19, the system of any of Examples 1-18, wherein the casing is configured to be disposed in a heat-exchange cavity.

In an Example 20, the system of Example 19, the heat-exchange cavity comprising at least one of an underground water storage reservoir, an above-ground water storage reservoir, and a borehole.

In an Example 21, the system of any of Examples 1-20, further comprising an additional casing.

In an Example 22, the system of Example 21, wherein the casing is configured to be disposed in a first heat-exchange cavity, and wherein the additional casing is configured to be disposed at a second heat-exchange cavity.

In an Example 23, the system of Example 22, further comprising a water moving apparatus configured to move water from the first heat-exchange cavity to the second heat-exchange cavity and/or from the second heat-exchange cavity to the first heat-exchange cavity.

In an Example 24, a method includes: positioning a coil assembly within a casing and positioning the casing within a heat-exchange cavity, the coil assembly comprising: a supply inlet configured to receive heat exchange fluid; a first manifold disposed downstream of the supply inlet, the first manifold comprising a supply conduit and a plurality of manifold outlets; a plurality of exchange conduits, wherein each exchange conduit is coupled, at a first end, to one of the plurality of manifold outlets; a second manifold disposed downstream of the first manifold, the second manifold comprising a return conduit and a plurality of manifold inlets, wherein each exchange conduit is coupled, at a second end, to one of the plurality of manifold inlets; and a return outlet configured to return the heat-exchange fluid.

In an Example 25, the method of Example 24, further comprising creating the heat-exchange cavity.

In an Example 26, the method of Example 25, wherein creating the heat-exchange cavity comprises drilling a borehole.

In an Example 27, the method of Example 25, wherein creating the heat-exchange cavity comprises creating an underground water storage reservoir.

In an Example 28, the method of any of Examples 24-27, the casing comprising an annular wall.

In an Example 29, the method of Example 28, the casing further comprising a lower wall at least partially closing a first end of the annular wall.

In an Example 30, the method of either of Examples 28 or 29, the casing further comprising an upper wall at least partially closing a second end of the annular wall.

In an Example 31, the method of any of Examples 28-30, the casing further comprising at least one aperture defined in the annular wall, the at least one aperture being configured to allow water to pass therethrough.

In an Example 32, the method of any of Examples 24-31, further comprising positioning at least one additional coil assembly within the casing.

In an Example 33, the method of Example 32, further comprising operatively coupling the at least one additional coil assembly to the coil assembly.

In an Example 34, the method of Example 33, wherein operatively coupling the at least one additional coil assembly to the coil assembly comprises coupling the coil assembly and the at least one additional coil assembly in series and/or in parallel.

In an Example 35, the method of any of Examples 24-34, wherein at least one of the first manifold and the second manifold has a length of at least approximately three feet.

In an Example 36, the method of any of Examples 24-35, the plurality of exchange conduits comprising between 75 and 125 exchange conduits.

In an Example 37, the method of Example 36, the plurality of exchange conduits comprising 117 exchange conduits.

In an Example 38, the method of any of Examples 24-37, each of the plurality of exchange conduits having a length of between at least approximately 15 feet and 25 feet.

In an Example 39, the method of Example 38, each of the plurality of exchange conduits having a length of at least approximately 19.5 feet.

In an Example 40, the method of any of Examples 24-39, wherein the plurality of exchange conduits are arranged in a parallel orientation with respect to each other.

In an Example 41, the method of any of Examples 24-40, wherein each of the plurality of exchange conduits is coiled with respect to a central axis.

In an Example 42, the method of Example 41, wherein at least one spacer is disposed between adjacent loops of the at least one of the plurality of exchange conduits.

In an Example 43, the method of Example 42, the at least one spacer comprising a plurality of spacers positioned to maintain an at least approximately constant gap between each pair of adjacent loops.

In an Example 44, the method of any of Examples 24-40, further comprising coiling each of the plurality of exchange conduits with respect to a central axis.

In an Example 45, the method of Example 44, further comprising positioning at least one spacer between adjacent loops of at least one of the plurality of exchange conduits.

In an Example 46, the method of Example 45, wherein the step of positioning the at least one spacer comprises positioning a plurality of spacers to maintain an at least approximately constant gap between each pair of adjacent loops.

In an Example 47, the method of any of Examples 24-46, the heat-exchange cavity comprising at least one of an underground water storage reservoir, an above-ground water storage reservoir, and a borehole.

In an Example 48, the method of any of Examples 24-47, further comprising positioning an additional casing within an additional heat-exchange cavity.

In an Example 49, the method of Example 48, further comprising moving water from the heat-exchange cavity to the additional heat-exchange cavity and/or from the additional heat-exchange cavity to the heat-exchange cavity.

In an Example 50, the method of any of Examples 24-49, the casing comprising a perforated polyvinyl chloride (PCV) pipe.

While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a geothermal system 100, in accordance with embodiments of the disclosed subject matter.

FIG. 2 is a schematic illustration of a heat-exchange assembly 200 disposed within a heat-exchange cavity 202, in accordance with embodiments of the disclosed subject matter.

FIG. 3 is a schematic illustration of heat-exchange assemblies 300 and 302 disposed within heat-exchange cavities 304 and 306, respectively, in accordance with embodiments of the disclosed subject matter.

FIGS. 4A and 4B depict an illustrative coil assembly 400 in accordance with embodiments of the disclosed subject matter.

FIG. 5 is a flow diagram depicting an illustrative method 500 of constructing a geothermal system in accordance with embodiments of the disclosure.

FIG. 6A is a cross-sectional side view of an illustrative geothermal system 600 having two illustrative heat-exchange assemblies 602 and 604 in accordance with embodiments of the disclosed subject matter.

FIG. 6B is a top view of a coil assembly of the illustrative geothermal system 600 depicted in FIG. 6A, in accordance with embodiments of the disclosed subject matter.

While the disclosed subject matter is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosed subject matter to the particular embodiments described. On the contrary, the disclosed subject matter is intended to cover all modifications, equivalents, and alternatives falling within the scope of the disclosed subject matter as defined by the appended claims.

As the terms are used herein with respect to ranges of measurements, “about” and “approximately” may be used, interchangeably, to refer to a measurement that includes the stated measurement and that also includes any measurements that are reasonably close to the stated measurement, but that may differ by a reasonably small amount such as will be understood, and readily ascertained, by individuals having ordinary skill in the relevant arts to be attributable to measurement error, differences in measurement and/or manufacturing equipment calibration, human error in reading and/or setting measurements, adjustments made to optimize performance and/or structural parameters in view of differences in measurements associated with other components, particular implementation scenarios, imprecise adjustment and/or manipulation of objects by a person or machine, and/or the like.

Although the term “block” may be used herein to connote different elements illustratively employed, the term should not be interpreted as implying any requirement of, or particular order among or between, various blocks disclosed herein. Similarly, although illustrative methods may be represented by one or more drawings (e.g., flow diagrams, communication flows, etc.), the drawings should not be interpreted as implying any requirement of, or particular order among or between, various steps disclosed herein. However, certain embodiments may require certain steps and/or certain orders between certain steps, as may be explicitly described herein and/or as may be understood from the nature of the steps themselves (e.g., the performance of some steps may depend on the outcome of a previous step). Additionally, a “set,” “subset,” or “group” of items (e.g., inputs, algorithms, data values, etc.) may include one or more items, and, similarly, a subset or subgroup of items may include one or more items. A “plurality” means more than one.

DETAILED DESCRIPTION

According to embodiments, a geothermal system is provided for facilitating a heat-exchange process, as described herein. The geothermal system is a closed-loop system that includes one or more heat-exchange assemblies configured to be disposed within a heat-exchange cavity defined in the ground. The heat-exchange assemblies include coil assemblies, having multiple, coiled, lengths of heat-exchange conduit. By implementing aspects of embodiments of the disclosed subject matter, it is estimated that embodiments of the system may facilitate obtaining at least approximately one ton of heating and/or cooling energy for each foot of depth within a region in which temperatures remain approximately constant (e.g., approximately equal to the year-long average air temperature). In embodiments, the heat-exchange assemblies described herein may be positioned such that, during periods of time when the ground water is at its lowest volume, the top of the heat-exchange assembly is at least approximately one foot below the water table. Thus, for example, embodiments of the geothermal system described herein may facilitate obtaining geothermal heat exchange using heat-exchange assemblies buried in boreholes that are drilled to a depth of at least approximately 40 to 60 feet.

FIG. 1 is a schematic illustration of a geothermal system 100, in accordance with embodiments of the disclosed subject matter. As illustrated, the system 100 includes a heat pump 102 configured to facilitate a heat-exchange process for heating and/or cooling at least a portion of a facility 104. According to various embodiments, the facility 104 may include one or more residences, one or more commercial buildings, one or more recreational vehicles, and/or any other structure that may include a heating and/or cooling system. The heat pump 102 is operatively coupled to a heat-exchange assembly 106 via a supply conduit 108 and a return conduit 110. According to embodiments, “operatively coupled” refers to an interaction that facilitates aspects of interactions described herein. That is, for example, that the heat pump 102 may be directly coupled, via the supply conduit 108 and return conduit 110, to the heat-exchange assembly 106. In other embodiments, the heat pump 102 may be indirectly coupled, via the supply conduit 108, the return conduit 110, and some other component (e.g., another heat-exchange assembly), to the heat-exchange assembly 106. The heat-exchange assembly 106 is configured to be disposed within a heat-exchange cavity 112 defined below the ground surface 114. In embodiments, the heat-exchange cavity 112 may be generally sealed except where apertures are provided for facilitating water circulation.

According to embodiments, the heat-exchange cavity 112 may include, for example, one or more underground water storage reservoirs, one or more above-ground water storage reservoirs, one or more boreholes, and/or the like. In embodiments, the heat-exchange cavity 112 may include a borehole having a diameter of between at least approximately 20 inches and 36 inches, and a depth of between approximately 15 feet and 100 feet. For example, a borehole may be drilled such that one or more heat-exchange assemblies 106 may be positioned at a depth of between at least approximately 40 feet and 60 feet. The heat-exchange cavity 112 may be at least partially filled with water, aggregate (e.g., grout, gravel, sand, crushed gravel, etc.), and/or the like. In embodiments, the heat-exchange cavity 112 may be, be similar to, include, or be included within, an underground water storage reservoir. Some examples of such underground water storage reservoirs, and their features, are described in U.S. Pat. No. 6,840,710, filed on May 15, 2002, and re-issued on Mar. 6, 2012; U.S. Pat. No. 7,192,218, filed on Feb. 23, 2005, and issued on Mar. 20, 2007; U.S. Pat. No. 7,972,080, filed on Mar. 14, 2008, and issued on Jul. 5, 2011; and U.S. Pat. No. 8,074,670, filed on Sep. 26, 2007, and issued on Dec. 13, 2011, the entirety of each of which is hereby expressly incorporated by reference herein for all purposes.

As depicted in FIG. 1, the heat-exchange assembly 106 includes a casing 118 and a coil assembly 120 disposed within the casing 118. The casing 118 may include an annular wall 122, a lower wall 124 that at least partially closes a first end 126 of the annular wall 122. The casing 118 also includes an upper wall 128 that at least partially closes a second end 130 of the annular wall 122. The casing 118 may include one or more apertures 132 extending through the annular wall 122 between an outer surface 134 of the annular wall 122 and an inner surface 136 of the annular wall. In this manner, the one or more apertures 132 may be configured to allow water to pass between a cavity 138 defined within the casing 118 and the heat-exchange cavity 112, outside of the casing 118. In embodiments, the casing 118 may be configured to have a size and shape that facilitates its insertion into the cavity 112. In embodiments, for example, the casing 118 may have an outer diameter of between at least approximately 20 inches and 30 inches (e.g., between 22 inches and 28 inches). The casing 118 may be manufactured using any suitable material including, for example, cement, HDPE, polyvinyl chloride (PVC), and/or the like. For example, the casing 118 may be a perforated PVC pipe.

As is further depicted in FIG. 1, the coil assembly 120 includes a supply inlet 140 configured to receive heat-exchange fluid. According to embodiments, heat-exchange fluid may be any fluid suitable for facilitating heat exchange such as, for example, water or a water-antifreeze mixture such as a mixture of water and propylene glycol. A first manifold 142 is disposed downstream of the supply inlet 140, and includes a supply conduit 144 and a number of manifold outlets 146. A number of exchange conduits 148 extend between the first manifold 142 and a second manifold 150. Each exchange conduit 148 is coupled, at a first end 152 to one of the manifold outlets 146, and is coupled, at a second end 154 to one of a number of manifold inlets 156 defined within the second manifold 150, which operatively couple exchange conduits 148 to a return conduit 158 defined within the second manifold 150. A return outlet 160 is disposed downstream of the second manifold and is configured to facilitate return of the heat-exchange fluid to the heat pump 102. In embodiments, the return outlet 160 may be configured to be coupled, via a conduit (not shown), to a supply inlet of another coil assembly 120. In this manner, coil assemblies 120 may be coupled together in series. In embodiments, two or more coil assemblies 120 may be coupled together in parallel. In other embodiments, coil assemblies 120 may be coupled in a combination of series and parallel configurations.

Moreover, as used herein, the terms “side wall,” “lower wall,” “upper wall,” “upward,” and “downward” are used to refer to the specific features to which they refer, but are characterized in the context of the illustrations for clarity and to describe relative orientations of features with respect to other features, and are not intended to imply any particular orientation of the system 100, or absolute (or preferred) orientations of features thereof. Additionally, “downstream” and “upstream” are used to refer to a relative position of components with respect to a fluid flow. Thus, for example, the system 100 may be configured such that heat-exchange fluid flows into the coil assembly via the supply inlet 140, through the first manifold 142, through the exchange conduits, through the second manifold 150, and out through the return outlet 160, in which case a first component is downstream from a second component where the first component is positioned such that the heat-exchange fluid reaches the second component before reaching the first component. Upstream is the opposite of downstream.

The illustrative system 100 shown in FIG. 1 is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the subject matter disclosed throughout this disclosure. Neither should the illustrative system 100 be interpreted as having any dependency or requirement related to any single component or combination of components illustrated in FIG. 1. For example, in embodiments, the illustrative system 100 may include additional components. Additionally, any one or more of the components depicted in FIG. 1 can be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated). For example, embodiments may include more than one conduit 108 and/or 110. Any number of other components or combinations of components can be integrated with the illustrative system 100 depicted in FIG. 1, all of which are considered to be within the ambit of this disclosure.

FIG. 2 is a schematic illustration of a heat-exchange assembly 200 disposed within a heat-exchange cavity 202, in accordance with embodiments of the disclosed subject matter. The heat-exchange assembly 200 may be, be similar to, include, or be included within, the heat-exchange assembly 106 depicted in FIG. 1. The implementation depicted in FIG. 2 is an example of many possible implementations of the technology described herein.

As shown, the heat-exchange assembly 200 includes a casing 204 configured to fit within the heat-exchange cavity 202. A first coil assembly 206 and a second coil assembly 208 are disposed within a cavity 210 defined within the casing 204. As shown, a first supply conduit 212 is coupled to a supply inlet 214 of the first coil assembly 206 and facilitates providing a heat-exchange fluid from a heat pump (not shown) to the first coil assembly 206. A second supply conduit 216 extends from a return outlet 218 of the first coil assembly 206 to a supply inlet 220 of the second coil assembly 208 and facilitates providing heat-exchange fluid from the first coil assembly 206 to the second coil assembly 208. In the illustrated embodiments, a return conduit 222 extends from a return outlet 224 of the second coil assembly 208 to the heat pump.

According to embodiments, any number of coil assemblies may be arranged in series and/or parallel. For example, a heat-exchange assembly 200 may include between one and 15 coil assemblies. In some embodiments, the heat-exchange assembly may include more than 15 coil assemblies. Additionally, heat-exchange assemblies may be configured in any number of different manners such as, for example, such that the return conduit 222 extends through an open space within the coil assemblies 206 and 208 (e.g., the return conduit 222 and/or the supply conduits 212 and 216 may be configured to extend through at least approximately a center region of each coil assembly). In this manner, the conduits 212, 216, and 222 may be protected, and additional diameter does not need to be provided within the casing to accommodate the conduits 212, 216, and 222. Additionally, the supply and return conduits may be configured to pass through at least approximately centrally-located apertures in the upper and/or lower walls of the casing. In this manner, embodiments may facilitate providing a modular system that can be scaled up or down by adding or removing heat-exchange assemblies, each of which may be manufactured in an identical, or at least approximately identical manner. In this manner, also, the supply and return conduits may be manufactured without having to incorporate additional curves and bends for moving the conduits around the loop assemblies and into and out of the casing apertures, thereby potentially saving in manufacturing and/or assembly cost and complexity.

The illustrative implementation shown in FIG. 2 is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the subject matter disclosed throughout this disclosure. Neither should the illustrative implementation be interpreted as having any dependency or requirement related to any single component or combination of components illustrated in FIG. 2. For example, in embodiments, the illustrative implementation may include additional components. Additionally, any one or more of the components depicted in FIG. 2 can be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated). Any number of other components or combinations of components can be integrated with the illustrative implementation depicted in FIG. 2, all of which are considered to be within the ambit of this disclosure.

FIG. 3 is a schematic illustration of heat-exchange assemblies 300 and 302 disposed within heat-exchange cavities 304 and 306, respectively, in accordance with embodiments of the disclosed subject matter. The heat-exchange cavity 304 and/or 306 may be, be similar to, include, or be included within, the heat-exchange cavity 112 depicted in FIG. 1, and/or the heat-exchange cavity 202 depicted in FIG. 2; and the heat-exchange assemblies 300 and/or 302 may be, be similar to, include, or be included within, the heat-exchange assembly 106 depicted in FIG. 1 and/or the heat-exchange assembly 200 depicted in FIG. 2.

As shown in FIG. 3, a pump 308 may be provided to facilitate moving water, via a conduit 310, from the first heat-exchange cavity 304 to the second heat-exchange cavity 306 and/or from the second heat-exchange cavity 306 to the first heat-exchange cavity 304. In this manner, water may be circulated between the heat-exchange cavities 304 and 306, thereby facilitating heat dissipation from the water. In embodiments, a pump may be used to circulate water between a heat-exchange cavity and a reservoir or other water source.

The illustrative implementation shown in FIG. 3 is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the subject matter disclosed throughout this disclosure. Neither should the illustrative implementation be interpreted as having any dependency or requirement related to any single component or combination of components illustrated in FIG. 3. For example, in embodiments, the illustrative implementation may include additional components. Additionally, any one or more of the components depicted in FIG. 3 can be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated). Any number of other components or combinations of components can be integrated with the illustrative implementation depicted in FIG. 3, all of which are considered to be within the ambit of this disclosure.

As described above, embodiments of the subject matter disclosed herein include a coil assembly configured to facilitate heat exchange between a fluid disposed therein and the environment. FIGS. 4A and 4B depict an illustrative coil assembly 400 in accordance with embodiments of the disclosed subject matter. According to embodiments, the coil assembly 400 may be, be similar to, include, or be included within the coil assembly 106 depicted in FIG. 1, the heat exchange assemblies 206 and/or 208 depicted in FIG. 2, and/or the heat exchange assemblies 300 and/or 302 depicted in FIG. 3.

As shown, the coil assembly 400 includes a supply inlet 402 configured to receive heat-exchange fluid (e.g., from a heat pump). A first manifold 404 is disposed downstream of the supply inlet 402, and includes a supply conduit 406 and a number of manifold outlets 408. A number of exchange conduits 410 extend between the first manifold 404 and a second manifold 412. In embodiments, the coil assembly 400 may include any number of exchange conduits 410. For example, the coil assembly 400 may include, in embodiments, more than one exchange conduit 410, more than 10 exchange conduits 410, between 10 and 200 exchange conduits 410, between 75 and 125 exchange conduits 410, more than 200 exchange conduits 410, and/or the like. In embodiments, the number of exchange conduits, and/or the dimensions (e.g., width, length, etc.) of each exchange conduit may be configured to achieve desired thermal exchange efficiencies.

For example, in embodiments the coil assembly 400 may include 117 exchange conduits 410, arranged between the first and second manifolds 404 and 412, each of which may be at least approximately three feet in length. Each of the exchange conduits 410 may be any desired length such as, for example, between at least approximately one and thirty feet long, between at least approximately 15 feet and 25 feet, between at least approximately five and twenty feet long, and/or the like. For example, in embodiments, each of the exchange conduits 410 may be at least approximately 18 feet long. In other embodiments, each of the exchange conduits 410 may be at least approximately 19.5 feet. According to embodiments, the exchange conduits 410 may be manufactured using any material suitable for facilitating energy exchange. For example, the exchange conduits 410 may be made of high-density polyethylene (HDPE). In embodiments, the coil assembly 400 may be, be similar to, include, or be included within, a “Geo Hyperloop” available from TEVA Energy, LLC, of Altamonte Springs, Fla.

Each exchange conduit 410 is coupled, at a first end 414 to one of the manifold outlets 408, and is coupled, at a second end 416 to one of a number of manifold inlets 418 defined within the second manifold 412, which operatively couple exchange conduits 410 to a return conduit 420 defined within the second manifold 412. A return outlet 422 is disposed downstream of the second manifold 412 and is configured to facilitate return of the heat-exchange fluid to the heat pump.

According to embodiments, the supply inlet 402 may be disposed at a first end 424 of the first manifold 404, and a second end 426 of the first manifold 404 may be closed. Conversely, a first end 428 of the second manifold 412 (which may be oriented in a similar direction as the first end 424 of the first manifold 404) may be closed, while the return outlet 422 may be disposed at a second end 430 of the second manifold 412. In embodiments, the supply inlet 402 may be disposed at the second end 426 of the first manifold 404, the return outlet 422 may be disposed at the first end 428 of the second manifold 412, and/or the like. In embodiments, the supply inlet 402 and/or the return outlet may be configured to be coupled to connecting conduit (not shown) that facilitates coupling the coil assembly 400 to another coil assembly.

As is further shown in FIG. 4A, the coil assembly 400 may further include one or more support members 432 extending across the exchange conduits 410 and coupled to one or more of the exchange conduits 410. In embodiments, as shown in FIG. 4A, the coil assembly 400 may include two support members 432, a longitudinal axis of each of which is oriented at least approximately perpendicular to a longitudinal axis 432 of each exchange conduit 410, when the coil assembly 400 is in a first configuration, in which the coil assembly 400 is extended as shown in FIG. 4A. Each support member 432 may be coupled, at their respective intersections, to each exchange conduit 410. In this manner, the support members 432 facilitate maintaining the exchange conduits 410 in orientations such that the respective longitudinal axes 434 of each pair of adjacent exchange conduits 410 are at least approximately parallel to each other with a specified gap between them.

FIG. 4B is a conceptual top view of the coil assembly 400 in a second configuration, in which the coil assembly 400 is coiled in at least approximately a spiral shape with respect to a central axis 436. In embodiments, the central axis 436 may be, or be at least approximately parallel to, a central longitudinal axis 438 of the first manifold 404, a central longitudinal axis 440 of the second manifold 412, and/or the like. A number of spacers 442 are positioned to maintain an at least approximately constant gap 444 between adjacent loops 446 of the exchange conduits 410. In embodiments, each spacer 442 is coupled to one or more exchange conduits 410 of each adjacent loop 446. In embodiments, the spacers 442 may be removably and/or adjustably coupled to the loops 446 to facilitate an ability to adjust the coiled shape of the coil assembly 400. For example, in embodiments, each spacer 442 may include a fork-like structure having two generally c-shaped structures, each of which is configured to slide over a set of exchange conduits 410, with a support structure spanning the gap 444. A pivotable latch or other securing device may be disposed at either (or both) ends of the spacer 442 to secure it in place. In embodiments, each spacer 442 may be configured to be coupled to more than two adjacent loops 446. In embodiments, the coil assembly 400 may be coiled to create any number of desired loops 446 and, therefore, any desired dimensions of the coil assembly 400. For example, in embodiments, the coil assembly 400, when coiled into the second configuration, may have a diameter of between at least approximately one foot and three feet.

The illustrative coil assembly 400 shown in FIGS. 4A and 4B is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the subject matter disclosed throughout this disclosure. Neither should the illustrative coil assembly 400 be interpreted as having any dependency or requirement related to any single component or combination of components illustrated in FIGS. 4A and 4B. For example, in embodiments, the illustrative coil assembly 400 may include additional components. Additionally, any one or more of the components depicted in FIGS. 4A and 4B can be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated). Any number of other components or combinations of components can be integrated with the illustrative coil assembly 400 depicted in FIGS. 4A and 4B, all of which are considered to be within the ambit of this disclosure.

Embodiments of a geothermal system utilizing coil assemblies to facilitate heat exchange are described above. FIG. 5 is a flow diagram depicting an illustrative method 500 of constructing a geothermal system in accordance with embodiments of the disclosure. The geothermal system may be, for example, the system 100 depicted in FIG. 1 and/or a system including any of the components and/or implementations depicted in any of FIGS. 2, 3, 4A, and 5A, and/or the like. Embodiments of the method 500 include coiling exchange conduits around a central axis (block 502), and positioning at least one spacer between adjacent loops (block 504) to create a coil assembly. Positioning the at least one spacer may include positioning a number of spacers to maintain an at least approximately constant gap between each pair of adjacent loops. In embodiments, the coil assembly may be, be similar to, include, or be included within, the coil assembly 120 depicted in FIG. 1; the coil assemblies 206 and/or 208 depicted in FIG. 2; and/or the coil assembly 400 depicted in FIGS. 4A and 4B.

The method 500 also may include coupling the coil assembly inlet and outlet to a heat pump (block 506), and positioning the coil assembly within a casing (block 508) to create a heat-exchange assembly. In embodiments, the heat-exchange assembly may be, be similar to, include, or be included within, the heat-exchange assembly 106 depicted in FIG. 1; the heat-exchange assembly 200 depicted in FIG. 2; and/or the heat-exchange assemblies 300 and/or 302 depicted in FIG. 3. As depicted in FIG. 5, embodiments of the method 500 also include creating a heat-exchange cavity (block 510) and positioning the heat-exchange assembly within the heat-exchange cavity (block 512). In embodiments, the heat-exchange cavity may be, be similar to, include, or be included within, the heat-exchange cavity 112 depicted in FIG. 1; the heat-exchange cavity 202 depicted in FIG. 2; and/or the heat-exchange cavities 304 and/or 306 depicted in FIG. 3.

According to embodiments, the method 500 may include any number of other steps in addition to, or in lieu of, the illustrative steps described above. For example, embodiments of the method 500 further include positioning at least one additional coil assembly within the casing and operatively coupling the at least one additional coil assembly to the coil assembly. The coil assembly and the at least one additional coil assembly may be coupled in series, in parallel, or a combination thereof. Embodiments of the method 500 may include positioning an additional casing within an additional heat-exchange cavity. In embodiments, the method 500 may include moving water from the heat-exchange cavity to the additional heat exchange cavity and/or from the additional heat-exchange cavity to the heat-exchange cavity.

As described above, heat-exchange assemblies may include a coil one or more coil assemblies disposed within a casing. In embodiments, more than one (e.g., two or three or any other number) coil assemblies may be disposed within a casing according to any number of different configurations. For example, coil assemblies may be arranged so that at least approximately a desired amount of (or other characteristic of) the heat-exchange fluid-coil assembly surface interface is achieved. FIG. 6A is a cross-sectional side view of an illustrative geothermal system 600 having two illustrative heat-exchange assemblies 602 and 604 in accordance with embodiments of the disclosed subject matter; and FIG. 6B is a top-view diagram depicting a portion of the heat-exchange assembly 602 of FIG. 6A, in accordance with embodiments of the disclosed subject matter. According to embodiments, the heat-exchange assemblies 602 and/or 604 may be, be similar to, include, or be included within, the heat-exchange assembly 106 depicted in FIG. 1, the heat-exchange assemblies 206 and/or 208 depicted in FIG. 2; and/or the heat-exchange assemblies 300 and/or 302 depicted in FIG. 3. As shown in FIG. 6A, the system 600 may be configured to be scalable by configuring the heat-exchange assemblies 602 and 604 as modular assemblies that can be implemented together in any number of different configurations, and with any number of additional modular assemblies.

As shown, the first heat-exchange assembly 602 includes a casing 606 at least partially enclosing a cavity 608 within which is disposed a first coil assembly 610 a and a second coil assembly 610 b. According to embodiments, the coil assemblies 610 a and/or 610 b may be, be similar to, include, or be included within, the coil assembly 120 depicted in FIG. 1, the coil assemblies 206 and/or 208 depicted in FIG. 2, and/or the coil assembly 400 depicted in FIGS. 4A and 4B. As shown in FIGS. 6A and 6B, the first coil assembly 610 a may be positioned concentrically around the second coil assembly 610 b. The casing 606 includes an annular wall 612, a lower wall 614 that at least partially closes a first end 616 of the annular wall 612, and an upper wall 618 that at least partially closes a second end 620 of the annular wall 612. The annular wall 612 includes a number of apertures 622 and 624 defined therein, each of which extends from an outer surface 626 of the annular wall 612 to an inner surface 628 of the annular wall 612. In embodiments, the apertures 622 may be configured to receive a water circulation conduit 630 that may facilitate circulating water into and out of the cavity 610 defined within the casing 606. The aperture 624 may be configured to receive a supply conduit 632. An aperture 634 defined in the upper wall 618 may be configured to receive a return conduit 636 and/or to provide access to the cavity 610. An aperture 638 defined in the lower wall 614 may be configured to receive a return conduit 640 that is coupled to the second heat-exchange assembly 604.

Similarly, the second heat-exchange assembly 604 includes a casing 642 at least partially enclosing a cavity 644 within which is disposed a first coil assembly 646 a and a second coil assembly 646 b. The first coil assembly 646 a may be positioned concentrically around the second coil assembly 646 b. The casing 642 includes an annular wall 648, a lower wall 650 that at least partially closes a first end 652 of the annular wall 648, and an upper wall 654 that at least partially closes a second end 656 of the annular wall 648. The annular wall 648 includes a number of apertures 658 and 660 defined therein, each of which extends from an outer surface 662 of the annular wall 648 to an inner surface 664 of the annular wall 648. In embodiments, the apertures 662 may be configured to receive a water circulation conduit 666 that may facilitate circulating water into and out of the cavity 644 defined within the casing 642. The aperture 660 may be configured to receive a supply conduit 668. An aperture 670 defined in the upper wall 654 may be configured to receive a return conduit 640 and/or to provide access to the cavity 644. An aperture 672 defined in the lower wall 650 may be configured to receive a return conduit 640 that is coupled to the third heat-exchange assembly (not shown), and/or to facilitate drainage of water from within the cavity 644.

In embodiments, the heat-exchange assemblies 602 and 604 may be coupled in series or in parallel, and may be disposed within a heat-exchange cavity 674 having a lower floor 676, upon which the second heat-exchange assembly 604 may be configured to be disposed. A cavity cover 678 may be configured to optionally close an opening 680 to the cavity 674, defined in the surface 682 of the ground.

The illustrative geothermal system 600 shown in FIGS. 6A and 6B is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the subject matter disclosed throughout this disclosure. Neither should the illustrative geothermal system 600 be interpreted as having any dependency or requirement related to any single component or combination of components illustrated in FIGS. 6A and 6B. For example, in embodiments, the illustrative geothermal system 600 may include additional components. Additionally, any one or more of the components depicted in FIGS. 6A and 6B can be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated). Any number of other components or combinations of components can be integrated with the illustrative coil assembly 400 depicted in FIGS. 4A and 4B, all of which are considered to be within the ambit of this disclosure.

Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the disclosed subject matter. For example, while the embodiments described above refer to particular features, the scope of this disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the disclosed subject matter is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof. 

We claim:
 1. A heat-exchange system comprising: a casing; and a coil assembly disposed within the casing, the coil assembly comprising: a supply inlet configured to receive heat-exchange fluid; a first manifold disposed downstream of the supply inlet, the first manifold comprising a supply conduit and a plurality of manifold outlets; a plurality of exchange conduits, wherein each exchange conduit is coupled, at a first end, to one of the plurality of manifold outlets; a second manifold disposed downstream of the first manifold, the second manifold comprising a return conduit and a plurality of manifold inlets, wherein each exchange conduit is coupled, at a second end, to one of the plurality of manifold inlets; and a return outlet configured to return the heat-exchange fluid.
 2. The system of claim 1, the casing comprising a perforated polyvinyl chloride (PVC) pipe.
 3. The system of claim 1, the casing comprising an annular wall.
 4. The system of claim 3, the casing further comprising a lower wall at least partially closing a first end of the annular wall.
 5. The system of claim 4, the casing further comprising an upper wall at least partially closing a second end of the annular wall.
 6. The system of claim 3, the casing further comprising at least one aperture defined in the annular wall, the at least one aperture being configured to allow water to pass therethrough.
 7. The system of claim 1, further comprising at least one additional coil assembly disposed within the casing.
 8. The system of claim 7, wherein the at least one additional coil assembly is operatively coupled to the coil assembly.
 9. The system of claim 8, wherein the coil assembly and the at least one additional coil assembly are operatively coupled in series and/or in parallel.
 10. The system of claim 1, wherein at least one of the first manifold and the second manifold has a length of at least approximately three feet.
 11. The system of claim 1, the plurality of exchange conduits comprising between 75 and 125 exchange conduits.
 12. The system of claim 11, the plurality of exchange conduits comprising 117 exchange conduits.
 13. The system of claim 1, each of the plurality of exchange conduits having a length of between at least approximately 15 feet and 25 feet.
 14. The system of claim 13, each of the plurality of exchange conduits having a length of at least approximately 19.5 feet.
 15. The system of claim 1, wherein the plurality of exchange conduits are arranged in a parallel orientation with respect to each other.
 16. The system of claim 1, wherein at least one of the plurality of exchange conduits is coiled with respect to a central axis.
 17. The system of claim 16, further comprising at least one spacer disposed between adjacent loops of the at least one of the plurality of exchange conduits.
 18. The system of claim 17, the at least one spacer comprising a plurality of spacers positioned to maintain an at least approximately constant gap between each pair of adjacent loops.
 19. The system of claim 1, wherein the casing is configured to be disposed in a heat-exchange cavity, the heat-exchange cavity comprising at least one of an underground water storage reservoir, an above-ground water storage reservoir, and a borehole.
 20. A method, comprising: positioning a coil assembly within a casing, the coil assembly comprising: a supply inlet configured to receive heat exchange fluid; a first manifold disposed downstream of the supply inlet, the first manifold comprising a supply conduit and a plurality of manifold outlets; a plurality of exchange conduits, wherein each exchange conduit is coupled, at a first end, to one of the plurality of manifold outlets; a second manifold disposed downstream of the first manifold, the second manifold comprising a return conduit and a plurality of manifold inlets, wherein each exchange conduit is coupled, at a second end, to one of the plurality of manifold inlets; and a return outlet configured to return the heat exchange fluid; and positioning the casing within a heat-exchange cavity. 